From: Christian Borntraeger <borntraeger@de.ibm.com>
Date: Thu, 4 Oct 2018 14:42:43 +0200
Subject: KVM: s390: fix locking for crypto setting error path
Git-commit: 8e41bd54317b04f2bf03012a4ca8ab7360c9beef
Patch-mainline: v4.20-rc1
References: git-fixes

We need to unlock the kvm->lock mutex in the error case.

Reported-by: smatch
Fixes: 37940fb0b6a2c4bf101 ("KVM: s390: device attrs to enable/disable AP interpretation")
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 arch/s390/kvm/kvm-s390.c | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index a6230b00c1df..734d87d88eb3 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -859,8 +859,10 @@ static int kvm_s390_vm_set_crypto(struct kvm *kvm, struct kvm_device_attr *attr)
 	mutex_lock(&kvm->lock);
 	switch (attr->attr) {
 	case KVM_S390_VM_CRYPTO_ENABLE_AES_KW:
-		if (!test_kvm_facility(kvm, 76))
+		if (!test_kvm_facility(kvm, 76)) {
+			mutex_unlock(&kvm->lock);
 			return -EINVAL;
+		}
 		get_random_bytes(
 			kvm->arch.crypto.crycb->aes_wrapping_key_mask,
 			sizeof(kvm->arch.crypto.crycb->aes_wrapping_key_mask));
@@ -868,8 +870,10 @@ static int kvm_s390_vm_set_crypto(struct kvm *kvm, struct kvm_device_attr *attr)
 		VM_EVENT(kvm, 3, "%s", "ENABLE: AES keywrapping support");
 		break;
 	case KVM_S390_VM_CRYPTO_ENABLE_DEA_KW:
-		if (!test_kvm_facility(kvm, 76))
+		if (!test_kvm_facility(kvm, 76)) {
+			mutex_unlock(&kvm->lock);
 			return -EINVAL;
+		}
 		get_random_bytes(
 			kvm->arch.crypto.crycb->dea_wrapping_key_mask,
 			sizeof(kvm->arch.crypto.crycb->dea_wrapping_key_mask));
@@ -877,16 +881,20 @@ static int kvm_s390_vm_set_crypto(struct kvm *kvm, struct kvm_device_attr *attr)
 		VM_EVENT(kvm, 3, "%s", "ENABLE: DEA keywrapping support");
 		break;
 	case KVM_S390_VM_CRYPTO_DISABLE_AES_KW:
-		if (!test_kvm_facility(kvm, 76))
+		if (!test_kvm_facility(kvm, 76)) {
+			mutex_unlock(&kvm->lock);
 			return -EINVAL;
+		}
 		kvm->arch.crypto.aes_kw = 0;
 		memset(kvm->arch.crypto.crycb->aes_wrapping_key_mask, 0,
 			sizeof(kvm->arch.crypto.crycb->aes_wrapping_key_mask));
 		VM_EVENT(kvm, 3, "%s", "DISABLE: AES keywrapping support");
 		break;
 	case KVM_S390_VM_CRYPTO_DISABLE_DEA_KW:
-		if (!test_kvm_facility(kvm, 76))
+		if (!test_kvm_facility(kvm, 76)) {
+			mutex_unlock(&kvm->lock);
 			return -EINVAL;
+		}
 		kvm->arch.crypto.dea_kw = 0;
 		memset(kvm->arch.crypto.crycb->dea_wrapping_key_mask, 0,
 			sizeof(kvm->arch.crypto.crycb->dea_wrapping_key_mask));